1. Field of the Invention
The invention relates to a method for treatment of sludge, and more particularly to a method for treatment of sludge with a facultative membrane bioreactor.
2. Description of the Related Art
Currently, more than 50% of sewage treatment plants adopt aerobic activated sludge process to treat sewage. However, the process produces a large amount of excess sludge that has complicated components and does great harm to environment. Conventional methods for treating excess sludge mainly lie in that excess sludge is firstly dehydrated in a sewage plant and then packaged and transported for landfill, incineration, or composting and so on.
However, these conventional methods have disadvantages as below: (1) in order to make excess sludge dehydrated and transport the dehydrated excess sludge, the overall investment of sludge treatment system is large; (2) the relevant technology and equipment required for an incineration method are complicated, high energy consuming and high cost, and causes atmospheric pollution; (3) a sludge landfill method requires a high soil mechanics properties of sludge, a large area of space and high transportation cost, additionally, the method easily cause groundwater pollution and atmospheric pollution due to landfill smell; and (4) a composting method easily causes heavy metal pollution.